The present invention pertains generally to tools or jigs within which a hand held tool may be temporarily positioned for the purpose of modifying the last mentioned tool as, for example, removing an abrading disk from a mandrel chucked within a dental handpiece.
Frequent replacement of small abrading disks are necessary in dental laboratory work and over a day's time constitute considerable time consuming effort. Contributing to the problem is the fact that the abrading disks are held in place by a small mounting screw with mandrel rotation tends to tighten. By necessity the screw is quite small and requires considerable breakaway torque when removing. Heretofore, it has been necessary for the user to manually hold the handpiece in a manner preventing mandrel rotation while attempting to back out the mounting screw with a screwdriver. In work where many abrading disks are used each day, such as dental laboratory work, considerable effort is expended in removing and substituting new disks.
The known prior art discloses a number of tools having both nut retaining and fastener driving capabilities such as, for example, U.S. Pat. Nos. 1,390,071, 1,270,766, 1,260,698 and 1,677,473. The tools disclosed in said patents perform in the combined manner of a screwdriver and wrench with the wrench feature serving to loosen or tighten a lock nut on the threaded fastener.